Roof supporting jacks on a continuous miner



July 24, 1956 A. w. ALDER 2,756,034

ROOF SUPPORTING JAcKs ON A CONTINUOUS MINER Filed OCT.. 29, 1952 2 Sheets-Sheet l VW N 1 32 4 W N 4f Fa' 1 0 5 v J y LV] j m Qggr/ 4 i H 35 C 25 35 2 q v 29 32 33 3g k (lie/@mier i felder ROOF SUPPORTING JACKS ON A CONTINUOUS lVIlNER Alexander W. Calder, Glenshaw, Pa., assignor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application October 29, 1952, Serial No. 317,470

Claims. (Cl. 262-1) This invention relates to a mine roof supporting means associated with mining machinery and more particularly nited States Patent O to timber jacks `on a continuous miner for continuously v supporting the mine roof above the miner thereby to diminish the danger of roof falls and to protect the miner and its operator during the mining operation.

ln modern high production mining machinery and particularly in a Joy type continuous miner which rapidly removes and loads out the coal from a solid coal seam, it is highly desirable to provide efficient and readily adjustable means for continuously supporting the mine roof above the machine both during the coal removing operation and during repositioning of the miner with respect to the coal face as mining progresses. The present invention contemplates improvements over known types of roof supporting means in that the roof supports are carried by the mining machine and may be readily and quickly adjusted so that the mine roof above the machine is continuously supported during the mining operation. In accordance with the present invention a set of upright rear roof supporting jacks and a set of upright front roof supporting jacks are mounted on the continuous miner and the front jacks are carried and are adjustable by a pair of adjustable horizontal power jacks whereby the fro-nt roof supporting jacks may be quickly repositioned with respect to the miner as the working facey advances and the miner may move forwardly between the front jacks as the miner is advanced toward the coal face. While the jack structure of the present invention is shown associated with a continuous miner, it will be evident that it may be associated with other types of mining equipment such as a mobile loading machine or a coal cutting machine.

It is accordingly a primary object of the present invention to provide an improved mine roof supporting-means associated with a mining machine for continuously supporting the mine roof above the machine during the mining operation while permitting bodily movement of the machine with respect to the roof supporting means to advance the machine as mining progresses. Another object is to provide an improved timber jack structure mounted on a continuous miner for continuously supporting the mine roof during both the coal removing operation and during repositioning of the miner as mining progresses. Still another object is to provide an improved adjustable mounting structure for the timber jacks of a mining machine whereby the jacks may be adjusted into different roof supporting positions with respect to the machine. A further object is to provide pairs of walking jack devices arranged at opposite sides of the machine and operatively connected to the base of the machine. These and other objects and advantages of the invention will, however, hereinafter more fully appear in the course of the ensuing description.

In the accompanying drawings there is shown for purposes of illustration one form which the invention may assume in practice.

ICC

In these drawings:

Fig. l is a plan'view showing the miner in operating position in a mine, with the improved roof jack means mounted on the miner, and with the disintegrating head of the miner in position to make a vertical cut.

Fig. 2 is a side View of the miner and roof jack means shown in Fig. 1.

Fig. 3 is an end view of the miner and roof jack means shown in Figs. l and 2.

Fig. 4 is an enlarged fragmentary side view showing the jacks partially in vertical section to illustrate structural details.

Fig. 5 is a detail horizontal section taken on line 5--5 of Fig. 4.

Fig. 6 is a view similar to Fig. 1, but on a smaller scale, showing the miner and roof jack means with the miner advanced between the front jacks into a position to start a new cut.

Fig. 7 is a diagrammatic view illustrating the hydraulic fluid system.

The coal mining machine or so-called continuous miner with which the present invention is associated is generally designated 1 and may be of the same general type as that disclosed in the copending applications to John D. Russell, Serial No. 102,995, and John R. Sibley, Serial No. 102,996, both filed on July 5, 1949, and owned by the assignee of the present invention. Evidently, as stated above, the invention may be associated with other types of mining equipment.

The continuous miner is of the well-known Joy type and generally comprises a mobile base 2, desirably a crawler base, carrying a frame 3 which has swiveled thereon at 4 to turn about a vertical axis a frames. The swiveled frame 5 provides a horizontal guideway eX- tending in a direction radial to the swivel axis and guided for rectilinear movement along this gnideway is a movable support 6 on which a disintegrating head 7 is v pivoted at 3 to swing in vertical planes. The disintegrating head comprises a swingable head frame 9 which has guided thereon for movement in parallel vertical orbits, series of disintegrating elements 10 which serve to tear away and dislodge the coal of a solid coal seam as the head is sumped into the coal near the floor level, is swung upwardly in vertical planes about itspivot, and is finally retracted from the face at the roof level. Upon the completion of each vertical cut the swiveled frame 6 may be turned horizontally about its swivel axis to reposition the disintegrating head angularly with respect to the base frame, and a plurality of adjoining vertical cuts may be made across the face completely to remove a wide section of coal between the ribs. Upon completion of each series of laterally adjacent cuts across the coal face, the entire machine may be bodily advanced toward the face to a new position under the propulsion of the crawler base and the series of laterally adjacent swinging cuts above described are repeated. Since this type of continuous miner is well known in the art and is fully disclosed in the above mentioned copending applications, further description thereof is herein deemed unnecessary.

Now referring to the improved roof supporting means associated with the miner it will be noted that arranged at the sides of the mobile base 1 beyond the sides of the horizontally swingable frame 5 and located rearwardly of the movable support 6 are pairs of walking jack devices f comprising upright extensible roof supports or power jacks 15 herein desirably fluid operated jacks comprising f vertical uid cylinders 16 suitably secured to the tops of Vsupports in the form of saddles 20 for receiving and supporting a mine timbering element such as a conventional cross timber 21. When iiuid under pressure is supplied to the cylinders 16 beneath the pistons 18, the latter are moved upwardly to elevate the saddles 20 thereby to bring the cross timber up against the mine roof, and by trapping fluid in the cylinders, the cross timber may be firmly held in roof-supporting position.

Pivotally mounted on the jack cylinders 16 to swing in horizontal planes with respect to the machine base are extensible supports or power jacks herein desirably fluid jacks or rams comprising iiuid cylinders 26 having rearward circular bearing portions 27 surrounding and pivotally mounted at 28 on the upper portions of the vertical jack cylinders 16 and the latter have annular flanges 29 integral therewith which underlie and support the jack cylinders 26. Upper clamps 30 surround the upper portion of the jack cylinders 16 above the bearing portions 27 to hold the latter against upward displacement. Reciproeable in the horizontal uid cylinders 26 are doubleacting pistons 31 having piston rods 32 proiecting out wardly from the outer ends of the cylinders and these piston rods carry at their outer ends annular portions 33 which surround and are integrally secured to vertical extensible roof supports or roof jacks 34. These front jacks are located in advance of the rear jacks 15 and are likewise desirably of the Huid operated type comprising vertical` cylinders 35 containing oppositely reciprocable pistons 36 and 37. The lower pistons 37 have piston rods 33 extending downwardly below the cylinders and provided with lower pointed ends or feet 39 engageable with the mine `floor or bottom, and the pistons 36 have upwardly extending piston rods 40 extending above the cylinders and carrying supports or saddles 41at their upper ends for receiving and supporting a forwardly 1ocated cross timber 42. When fluid under pressure is suitably supplied to the cylinders 35 intermediate the upper and lower pistons 36 and 37 the latter are moved axially apart to bring the `pointed ends into engagement with `the mine oor and to raise the saddles 41 to bring the cross timber thereon firmly up against the mine roof. By trapping iiuid in these jack cylinders the cross timber may be firmly held in roof-supporting position.

Power means of any suitable form may be provided for swinging the horizontal jacks 25 in horizontal planes about their pivotal mountings on the rear jacks and herein, for illustrative purposes, there are shown extensible fluid jacks 45 having their cylinders suitably pivotally mounted onthe base frame 5 of the continuous miner and containing reciprocable pistons 46 having their piston rods 47 pivotally connected to lateral arms 48 integral with the bearing collars 27 of the jacks 25. Thus when fluid under pressure is suitably` supplied to the swing jacks 45 the horizontal jacks 25 may be swung horizontally about their pivots and when Huid is trapped in these swing jacks the horizontal jacks 25 may be firmly locked in adjusted position.

As shown diagrammatically in Fig. 7, a pump 50 has its suction side connected by conduit 51 to a uid reservoir or tank 52 and the discharge side of the pump is connected by conduit 53 to the pressure passage of a valve box 54 of a conventional control valve mechanism suitably mounted on the machine. The discharge passage of this valve box is connected by a return conduit 55 back to the tank 52. The valve box has horizontal bores containing conventional control valves 56, 57, 5S and 59, each provided with a suitable control handle, and the bore containing the control valve 56 is connected by conduits 60 and 61 to the opposite ends of the swing jacks 45 while the bore containing the control valve 57 is connected by conduits 62 and 63 to the opposite ends of the vertical cylinders of the rear roof supports or timber jacks 15. The bore containing the control valve 5S is connected by a branched conduit 64 to the remote ends of the vertical cylinders 35 of the front timber jacks 34 and by a branched conduit 65 connected to the vertical cylinders 35 at points between the upper and lower pistons 36 and 37. The bore containing the control valve 59 is connected by conduits 66 and 67 to the opposite ends of the horizontal jack cylinders 26.

The mode of operation of the improved roof jack means `.vill now be described. When the continuous miner is in the coal removing position shown in Fig. l, fluid under pressure may be supplied to the rear roof supports or timber jacks 15 to hold therear cross timber 21 firmly against the mine roof and the swing cylinders 45 for the horizontal jack cylinders 26 may be operated to locate the front cross timber 42 in its forward position with respect to the miner as shown in Fig. l, and fluid under pressure may be supplied to the front roof supports or timber jacks 34 to hold the front cross timber 42 firmly against the mine roof. As the digging or disintegrating head 7 of the continuous miner is operated to remove by successive vertical cuts a wide segment of coal completely across the coal face between the ribs and the movable support 6 which supports the digging head is in retracted position on the frame 5 of the miner-base, the rear timber jacks 15 may be released to remove the roof supporting pressure from the cross timber 21 and the entire machine may be advanced bodily between the front jacks 34 while the latter remain in roof supporting position, to the position shown in Fig. 6. As the machine advances between the front timber jacks the distance between the front jacks 34 and the rear jacks 15 decreases necessitating shortening of the horizontal jacks 25 and, at that time, the control valve 59 may be positioned to vent fluid from the horizontal jack cylinders to permit the pistons 31 to move inwardly as necessary. If desired, instead of moving the control valve 59 into cylinder venting position, a conventional pressure relief valve set to open at a predetermined pressure may be connected in the uid conduit 67 so that when the pressure within the horizontal jack cylinders becomes excessive the fluid may be vented back to the tank through a usual return conduit. Also, if desired, conventional Greer accumulators may be associated with the front and rear roof supporting jacks for cushioning the jacks when subjected to sudden shocks, in a wellknown manner. When the continuous miner assumes its newly advanced position shown in Fig. 6, fluid under pressure may be supplied to the swing jacks 45 and the horizontal jacks 25 under the control of the control valves 56 and 59, to swing the horizontal jacks forwardly and inwardly with respect to the miner-base into the position shown in Fig. l and the front timber jacks 34 may then be u extended, under the control of the control valve 58, to

raise the cross timber 42 into roof supporting position. Thus by successively extending, repositioning and releasing the pairs of front and rear timber jacks as the continuous miner is operated to remove and load out the coal from the solid coal seam and is advanced to a new operating position the mine roof above the miner may be continuously supported thereby to protect both the miner and its operator against the danger of roof-falls or cave-ins.

As a result of this invention an improved mine roof supporting means associated with a mining machine is provided wherein the mine roof above the machine may be continuously supported both during the coal-removing operation and during repositioning of the miner with respect to the coal facethereby to diminish the danger of roof-falls and to protect the miner and its operator. The improved mounting means for the pairs of front and rear roof supports or timber jacks on the machine enables ready and rapid adjustment of the jacks so that the mine roof above the machine is continuously supported during the mining operation. By the provision of the swngable, extensible horizontal jacks by which the front timber jacks are supported the latter may be successively advanced or repositioned each time the rear timber jacks on the machine are advanced so that the cross timbers ymay be moved forwardly step by step in roof supporting positions as mining progresses. The improved jack structure is relatively simple and rugged in design, well adapted for its intended purpose, and may be readily applied to a continuous miner of a standard construction without substantial modification. These and other advantages of the invention will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, a mining machine having a mobile base provided with self-contained propelling means and adapted to travel over the floor of a mine, rear jack devices at the opposite sides of said base for holding a roofsupporting cross member up against the mine roof, front jack devices at the opposite sides of said base for holding a roof-supporting cross member up against the mine roof in advance of said first mentioned cross member, means for connecting said jack devices to said base of the machine including adjustable connecting means for permitting movement of said rear jack devices, when released, forwardly with said base relative to said front jack devices while the latter are maintained in crossmember-holding, roof-supporting position, and means for effecting alternate operation of said pairs of front and rear jack devices.

2. In combination, a mining machine having a mobile base provided with self-contained propelling means and adapted to travel over the oor of a mine, a pair of rear roof-supporting jacks arranged at the opposite sides of said machine-base, a pair of front roof-supporting jacks arranged at opposite sides of said base and between which the machine may be bodily advanced by its propelling means when said rear jacks are released, adjustable connections between the machine and said pair of front jacks for connecting the latter to the base of the machine and operable to permit bodily movement of the machine between said front jacks while the latter remain in roofsupporting position and connected to said base of the machine, and means for effecting alternate operation of said pairs of front and rear jacks.

3. In combination, a mining machine having a mobile base adapted to travel over the floor of a mine, a pair of extensible rearwardly located roof-supporting jack devices and a pair of extensible forwardly located roof-supporting jack devices, said jack devices disposed at the opposite sides of said base and positionable from near the sides of said base laterally outwardly a substantial distance bevond the sides of said base, means for connecting said rear jack devices to the sides of said base, means for pivotally connecting said front jack devices to said rear jack devices to swing horizontally with respect thereto, and self-contained propelling means for said base for effecting bodily movement of the machine relative to said front jack devices while the latter remain in firm roofsupporting position.

4. In combination, a mining machine comprising a mobile base having propelling means for advancing the same over the floor of a mine, and roof jack devices at the opposite sides of said base comprising a pair of extensible rear roof-supporting jacks, a pair of extensible front roof-supporting jacks in advance of said rear jacks, and means for connecting said pairs of jacks to the opposite sides of said base including horizontally adjustable connections for said front jacks for advancing the latter relative to said base and to said rear jacks while the latter remain in extended roof-supporting position, said base propelling means operable to effect bodily advance of said base relative to said front jacks while the latter remain in firm roof-supporting position, said adjustable connections adjusting automatically to permit said base to advance as aforesaid.

5. A combination as set forth in claim 4 wherein said power operated whereby said connections may move said horizontally adjustable connections are extensible and front jacks horizontally relative to said base.

6. In combination, a mining machine having a mobile base having self-contained propelling means and adapted to travel over the floor of a mine, a pair of extensible power roof-supporting jacks arranged vertically at the sides of said base for supporting a roof-supporting cross member against the mine roof, a pair of extensible power roof-supporting jacks arranged vertically at the sides of said base in advance of said first mentioned jacks for supporting a parallel roof-supporting cross member against the mine roof in advance of said first mentioned cross member, and means for connecting said front jacks to the base for advancing said front jacks, when the latter are released, relative to said base and said rear jacks to advance the front cross member relative to the rear cross member.

7. A combination as set forth in claim 6 wherein said connecting means includes horizontal power extensible connections for said front jacks operable to permit the machine to be advanced bodily by its propelling means relative to said front jacks while the latter remain in f irm roof-supporting position.

8. A combination as set forth in claim 7 wherein said power extensible connections are operable to permit movement of said rear jacks, when the latter are released, forwardly with the base as the latter is advanced by its propelling means between said front jacks, and said extensible connections automatically decreasing in length as the base is advanced as aforesaid.

9. In combination, a mining machine comprising a mobile base having self-contained propelling means and adapted to travel over the floor of a mine, a pair of rear roof-supporting jacks connected to said base at the sides thereof, a pair of front roof-supporting jacks connected to said base and between which the base is adapted bodily to advance by its propelling means when said rear jacks are released, adjustable connections between the machine and said front jacks for connecting the latter to said base and operable to permit bodily movement of said base between said front jacks while the latter remain in roof-supporting position and connected to said base, said adjustable connections mounted to swing horizontally and pivotally connected to said rear jacks respectively, and means for effecting alternate operation of said pairs of front and rear jacks.

10. In combination, a mining machine having a mobile base having self-contained propelling means and adapted to travel over the fioor of a mine, a plurality of extensible jack devices connected to said base and comprising a pair of rear roof-supporting jacks at the sides of said base and a pair of front roof-supporting jacks at the sides of said base, and means for connecting said jacks to said base including adjustable connections for said front jacks for adjusting the latter forwardly relative to said base and said rear jacks while the latter remain firmly in roof-supporting position, said self-contained propelling means effecting bodily movement of said base relative to said front jack devices while the latter remain in firm roofsupporting position.

References Cited in the file of this patent UNITED STATES PATENTS Re. 17,467 Crawford Oct. 22, 1929 1,480,733 Morgan Jan. 15, 1924 1,704,866 Morgan Mar. 12, 1929 1,704,918 Morgan Mar. 12, 1929 1,755,700 Morgan Apr. 22, 1930 2,420,755 Mavor May 20, 1947 2,574,857 Ball Nov. 13, 1951 2,641,906 Knights et al July 16, 1953 FOREIGN PATENTS 631,747 Great Britain Nov. 9, 1949 

